GEAR 6Y0976 - Caterpillar

Illustration 1 g06308660
(1) Pilot pump
(2) Pilot filter
(3) Implement pump
(4) Tilt control lever
(5) Lift control lever
(6) Hydraulic lockout switch
(7) Fan pump (implement cooler)
(8) Accumulator (implement pilot)
(9) Expansion tank (if equipped)
(10) Tilt cylinders
(11) Manual lowering valve
(12) Lift cylinders
(13) Control valves
(14) Implement ECM
(15) Implement and fan hydraulic oil tank
(16) Implement cooler bypass valve
(17) Implement hydraulic oil cooler
(18) Optional joystick (tilt and lift control)The 994K Wheel Loader is electro-hydraulically controlled. The machine uses hydraulic power that is controlled by electronics to move the actuators. The electrohydraulic system is composed of the following systems: the main hydraulic system, the pilot system, and the implement electronic control system.The pilot system consists of the following three components:
Hydraulic fan pump
Pilot pressure reducing valve
Pilot control actuators and accumulatorThe pilot control actuators are attached to the main control valve. The actuators control the shifting of the stems. Also, the main control valve is equipped with a shuttle valve (ball resolver) and a dead engine lower valve. The shuttle valve and the dead engine lower valve are used to control pilot oil to the pilot control actuators. The valves allow for lowering the work tool with a dead engine.The 994K electrohydraulic implement is similar to the 990K, except the 990K has just one set of valves for each function, whereas the 994K has a left and right valve section.The implement electronic control system consists of the following components:
Implement Electronic Control Module (ECM)
Operator controls
Lift lever position sensor
Tilt lever position sensor
Linkage position sensors
Lift linkage position sensor
Tilt linkage position sensor
Hydraulic lockout switch
Pilot control solenoids
Float valve solenoids
Pump solenoids